Patent GB-634163-A (GB)
Title: Counting mechanisms
IPC: G06M1/14
Filed: 1946-06-22
Abstract: 634,163. Counting-apparatus. TOLEDO SCALE CO. June 22, 1946, No. 18786. Convention date, Oct. 24, 1942. [Class 106 (i)] A continuous gearing type transfer mechanism for counting-apparatus has part of its gear-train carried on a frame to which an oscillatory movement is imparted by a cam, the movement being such that the creep of the higher order wheels is counteracted for the major part of the cycle of the low order mechanism and the movement of the wheels operates to move the higher order dial only over the last part of the cycle. The cam, and thus the whole mechanism, can turn in either direction. A dash-pot slows the oscillations so that at high speed operation they do not follow the cam and the creep is not counteracted. An input shaft 10 rotates, via pinions 18, 19, a shaft 21 to which is rigidly connected a tens and units drum 24 and a pinion 20 which meshes with both parts 36, 37 of an anti-backlash gear 32, one part being riveted to a hub 33, the other part being freely rotatable on the hub and springs 38 interconnecting them. On the hub 33 is a pinion 39 which, via an idler gear 40 and drive gear 42, rotates a countershaft 43 upon which are pinions 44, 45 driving large annular gears 46, 48 fastened to hundreds drums 47, 49 respectively. The countershaft 43 is journalled in T-brackets 28, 29 which are pivotally supported by the shaft 21 and connected by tubes 30, 31, and the gears 32, 39 and 40 are carried on shafts which are supported by brackets 35, 41 depending from the tubes 30, 31, so that all these shafts will move with the T-brackets 28, 29 if these pivot about the shaft 21. An arm 50 has two legs pivotally mounted on a cross-bar 52 extending between tubular members 14 which connect triangular members 12, 13, its upper end being bifurcated and extending round the tube 30 and a roller 54 being carried in a clip 55 which is pivoted on a pin 56 extending between the lower legs of the arm. The roller is urged by a spring 57 against a cam 53 which has five steps and is secured to the hub 26 of the tens and units drum 24. A spring 59 tends to rotate the bracket 29 anti-clockwise (Fig. VI) about the shaft 21, thus allowing the roller 54 to maintain contact with the cam. When the shaft 10 is being rotated to increase the reading of the counter, the cam rotates clockwise (Fig. VII). Over the gradual fall 67 of the cam, the bracket 29 moves to the left, the pinions 44, 45 moving with it. This amount of motion is such that it just compensates for the rotation of the bottom of these pinions to the right, so that there is no motion transmitted to the drums 47, 49. But when the roller contacts the steep rise 68 of the cam, the arm 50 moves sharply to the right and the drums 47, 49 rotate to show the next digit. The rise 68 is not sufficiently steep to prevent rotation of the cam in the opposite, subtractive, direction. In the example shown, the section 68 of the cam is 1/19th of the section 67 so that the hundreds drums do not move until the units drum reaches 95, and the units drum is marked in fives from 0 to 95, these numbers being repeated five times so that the hundreds drums make five moves for each complete rotation of the tens and units drum. A dashpot 69 damps the movement of the bracket 29 so that at high speeds the roller 54 cannot follow the cam and the mechanism becomes a direct gear driven one, with all the drums moving continuously. Viewing screens 76, 77 are provided so that readings can be taken front and rear, one of the hundreds drums serving for each and the tens and units drum having dual markings. Printing types are also provided on the tens and units drum and on one of the hundreds drums. In a modification (Figs. X to XVII, not shown), four smaller separate drums are provided, one each for units, tens, hundreds and thousands, and mechanism similar to that described is provided between successive drums, each cam in this case having only one steep rise and one gradual fall so that a complete revolution of a drum advances the next drum one digit.